Width is measured across the chest below the sleeves from seam to seam. Height is measured from the bottom of the shirt to the highest point on the shoulder (where the seam meets the neck).

Please note that each product has its own specific sizing chart.
SizeWidth (inches)Height (inches)
Adult Small 17.528
Adult Medium 1929.5
Adult Large 21.530
Adult XL 23.530.5
Adult 2XL 2632